1. Field of the Invention
The present invention relates generally to improvements in air conditioning apparatus, and more particularly, but not by way of limitation, to modularly installed air conditioning equipment making use of heat pump assemblies.
2. Description of the Prior Art
The prior art contains many teachings of heating and cooling units of the type utilizing a fan blowing air which has been heated or cooled by a heat exchanger apparatus. Generally, the prior art heating and cooling units were designed to provide heated or cooled air only to one room area, thereby requiring field installation of one unit for each room area to be heated and cooled. The bulky external plumbing and consumption of floor space which were entailed with prior art units were reduced by the air conditioning unit described in the Applicant's U.S. Pat. No. 3,722,580, which disclosed a modular unit which could heat or cool two horizontally adjacent room areas separated by a common vertical partition within which the unit was installed. Each modular unit contained two independent room units, which were separated by a riser duct; and the modular units could be vertically stacked for use on separate floors of a multiple-story building. Pipes which extended vertically within the riser duct supplied heat exchange fluid to the unit on each floor. The air conditioning unit thus disclosed was not only smaller, but was also simpler and less costly to install than the prior art units.
Further advances in ease and flexibility of installation and operation of modular air conditioning units were disclosed in the Applicant's U.S. Pat. No. 4,127,162. The major components of the modular unit there disclosed could be arranged within a frame so as to face any one of three access sides of the unit, any one of which could be positioned adjacent to the room area to be heated or cooled. Thus, for example, a unit's blower could be oriented on the side of the frame providing the best air flow arrangement within the room being heated or cooled. Furthermore, all of the major components of the individual units were designed to be easily removed and replaced, for convenient installation and service. In addition, the heat exchange apparatus was disposed downstream from the blower, rather than upstream as was generally the case in the prior art. This improvement permitted the use of a larger heat exchanger in the unit, allowing a more even air distribution in the exchanger and thus more efficient heating and cooling.
In the Applicant's U.S. Pat. No. 4,169,500, a double modular unit was disclosed for the heating and cooling of two horizontally adjacent room areas separated by a vertical partition. This double unit featured many of the advantages of the above-mentioned patents, including multiple access sides and disposition of the heat exchanger downstream from the blower in each unit.
While the improvements embodied in these previous patents and applications have proven significant, subsequent developments have indicated that further improvements of the economy and efficiency of the unit disclosed in the parent application may be accomplished by the use of the heat pump assemblies. The principle of the heat pump, also known as reverse air conditioning, has been well known for over a century. However, its application to air conditioning equipment was not widely considered prior to 1973, when the domestic fuel shortage stimulated a search for methods of conserving energy.
The principle of the heat pump is based on the use of a closed loop of refrigerant fluid to move heat from one area to be dissipated at another area. Instead of generating heat, as does the conventional fossil fuel furnace, the heat pump uses energy to move energy, and does its job at about half the operating cost required by conventional air conditioning apparatus.
A typical water-source heat pump apparatus has an air-to-refrigerant heat exchanger and a water-to-refrigerant heat exchanger. Initially, a compressor compresses the refrigerant, and by means of precision valving, the compressed fluid is passed to either the water-to-refrigerant heat exchanger or the air-to-refrigerant heat exchanger. The water-to-refrigerant coil receives a stream of water from a water source and discharges water which is either higher or lower in temperature, depending on whether the heat pump is in the heating or cooling mode. The air-to-refrigerant exchanger receives a stream of air from the room to be heated or cooled, and discharges air which is either hotter or cooler than the intake air, depending on the heat pump's operational mode. In the cooling mode of the heat pump, the refrigerant is first passed through the water-to-refrigerant heat exchanger and then through the air-to-refrigerant exchanger. In the heating mode, this is reversed, with the refrigerant first being passed through the air-to-refrigerant exchanger and then through the water-to-refrigerant coil. In effect, during winter months, heat is extracted from the water stream by the refrigerant, which in turn transfers the heat to room air. In the summer months, heat from room air is picked up by the refrigerant, which in turn transfers the heat to the water stream.
While the modular air conditioning units employing heat pump assemblies have been utilized previously, prior art units do not provide ease of access, and such units take up an undue amount of floor space. Accordingly, it would be desirable to provide a modular air conditioning unit which offers the economic advantages of the heat pump while providing ease of access, flexibility of component placement and compactness of design.